[Acebaraka]

Hello all,

I've been looking through the forum and can't find anything on this so thought I'd ask.

My airbag light came on a while ago so consulting this excellent forum bought a switched interface and downloaded Multiscan. Got those two things talking to each other and then today had a go at getting the light off.

Did a scan which said my airbag module was an MY97. I connected to this module and it shows an error code

0B-Drivers Pre-Tensioner

Great I thought classic connector problem. Tried to clear the fault but it wouldn't. Anyway carried on and d/c the battery and waited. Then looked at both drivers and passengers connectors. Both look clean, tight and generally ok. Put some contact cleaner on anyway and on/off a few times. I then measured the resistance of the the pretensioners both sides were the same and 0.5 ohm also neither terminal shorted to earth (earth taken from pretensioner body)

So put it back together and reconnected the battery. Re-connected to the airbag module and tried to clear the code. Still wouldn't clear the fault.

Am I missing something in the Multiscan process? One thing I was wondering about is there are two options of module to connect to the 'TRW Airbag MY97' one that the scan came up with or TRW2 Airbag (with pretensioners)' This one worried me slightly as it asked me to d/c squibs and insert resistors which I didn't have so I have not tried to connect to this one. Could this be the one I need to connect to?

Also I noticed;

-that the module said battery voltage 'ok' and looks good to me on a multimeter at the battery anyway.

-that the module was showing 'passenger present' even when they were not. I think this is probably just that I have the key that disables the passenger side for a baby seat in the active position.

I have attached a couple of Multiscan screen shots

Any ideas would be much appreciated.

 

[Persimmon]

Hello all,

I've been looking through the forum and can't find anything on this so thought I'd ask.

My airbag light came on a while ago so consulting this excellent forum bought a switched interface and downloaded Multiscan. Got those two things talking to each other and then today had a go at getting the light off.

Did a scan which said my airbag module was an MY97. I connected to this module and it shows an error code

0B-Drivers Pre-Tensioner

Great I thought classic connector problem. Tried to clear the fault but it wouldn't. Anyway carried on and d/c the battery and waited. Then looked at both drivers and passengers connectors. Both look clean, tight and generally ok. Put some contact cleaner on anyway and on/off a few times. I then measured the resistance of the the pretensioners both sides were the same and 0.5 ohm also neither terminal shorted to earth (earth taken from pretensioner body)

So put it back together and reconnected the battery. Re-connected to the airbag module and tried to clear the code. Still wouldn't clear the fault.

Am I missing something in the Multiscan process? One thing I was wondering about is there are two options of module to connect to the 'TRW Airbag MY97' one that the scan came up with or TRW2 Airbag (with pretensioners)' This one worried me slightly as it asked me to d/c squibs and insert resistors which I didn't have so I have not tried to connect to this one. Could this be the one I need to connect to?

Also I noticed;

-that the module said battery voltage 'ok' and looks good to me on a multimeter at the battery anyway.

-that the module was showing 'passenger present' even when they were not. I think this is probably just that I have the key that disables the passenger side for a baby seat in the active position.

I have attached a couple of Multiscan screen shots

Any ideas would be much appreciated.

Rather than just trying to clear the fault using the software and given the obvious checks you have done it might be worth fixing the problem by getting a replacement seat belt pretensioner.
Mind you "Drivers pre tensioner " needs replacing may well mean the opposite. Remember the car was designed as a leftie as this is an Alfa so I would suggest replacing the passenger seat belt pre tensioner. Then clear using the software

 

[Acebaraka]

Thats sort of what I was thinking but I was also thinking that maybe if a pre-tensioner unit had a fault it would record a different resistance. Does anyone know what value to expect for a pre-tensioner?

I might try swapping drivers for passenger and visa-versa by extending the wires, that should show a change in fault I guess.

 

[spankdanny]

If you are using a switched interface in the socket under the steering wheel then you must have a phase 2 or 3 car which shouldn't use the my97 module. Ignore the warnings and use the other setting but don't be sat in the car whilst connecting just in case. I have cleared many faults in situ and never had a problem but better to be safe than sorry.

 

[Mr Sunseeker]

Thats sort of what I was thinking but I was also thinking that maybe if a pre-tensioner unit had a fault it would record a different resistance. Does anyone know what value to expect for a pre-tensioner?

I might try swapping drivers for passenger and visa-versa by extending the wires, that should show a change in fault I guess.

I had exactly the same error and it was the passenger pre-tensioner, I have had two air bag faults in the last 12 months and both times it required a replacement pre-tensioner.

 

[cgc]

Could try FiatECUscan instead, see if it makes any difference.

 

[Acebaraka]

If you are using a switched interface in the socket under the steering wheel then you must have a phase 2 or 3 car which shouldn't use the my97 module. Ignore the warnings and use the other setting but don't be sat in the car whilst connecting just in case. I have cleared many faults in situ and never had a problem but better to be safe than sorry.

Its a 2001 Ph2 so interesting what you say about it not being the MY97 module. Just to check you have definitely connected to the other module (TRW Airbag 2 with pre-tensioners) without inserting the resistors and it was ok? I obviously wouldn't hold you responsible and wont sit in it but it would be very annoying for an airbag to go off :happy:

Also if I was thinking if it was the wrong module I was trying to connect to then it just wouldn't have connected? But it does and shows the error and other data from that module.

Does anyone happen to now the value of resistor you are supposed to insert?

 

[spankdanny]

Before MES was updated to work with the twr2 module then I used to clear faults using trw2scan software on the bench with an old airbag wiring loom and dummy resistors. Now I connect laptop direct to module in situ with the 3 pin connector, me having a later phase 1. I'm sure phase 2 owners do the same using the obd port. I've never heard of airbags going off during fault clearing.

 

[spankdanny]

I used to use 3ohm resistors.

 

[Acebaraka]

Ok Thanks, I'm going to have another play this week and see what I get.

 

[alfapash]

I use Fiatecuscan on both my phase 2's. I choose TRW2, last time it would not clear the faults until I ran my fingers over the wires from the connectors under the seat, smoothing them out , I think a bottle of water had rolled under the seat. Tried again and faults cleared straight away. Just check to see how the wires are looking. Another fix I remember someone saying was disconnect the battery for and hour, pull the connector under the seat apart and prise the connector that is connected to the wire open a tad with a stanley blade, the connector has a cross on the end. clean both terminals re-connect and re-connect the battery. I'm certain driver's side is actually the passenger side. Then try to clear the fault codes.

 

[Afco]

I had the same fault, also saying it was the pre tensioner. After changing the two the fault was still not eraseble. Then i changed the ECU still the same. So someone told me that it was the clockspring that was not OK. After changing the clockspring i could erase the fault with MES
Be shure to change it by the right one because many second hand suppliers pretend they are all the same for fase 1.2 and 3 however it is not the case. The partnumber is on the clockspring

 

[Acebaraka]

Thanks for the replies guys.

I tried connecting to the other module today despite the Multiscan scary warnings and it could not find the ecu but connected straight away to the MY97 module so that clears that up. Definitely the MY97 module.

Interesting what you say about the clockspring Afco as those could be my symptoms, it will not clear the fault even for half a second and my pre-tensioner connectors look good and both pre-tensioners have the same resistance. I am going to double check this with jump leads but they look alright it just won't go out even for a bit with whatever I do with them.

Just one question Afco, or anyone, what is the clockspring? I haven't heard of this at all.

Also even after you changed that would multiscan not turn it off? You had to use MES?

Thanks

 

[Afco]

Thanks for the replies guys.

I tried connecting to the other module today despite the Multiscan scary warnings and it could not find the ecu but connected straight away to the MY97 module so that clears that up. Definitely the MY97 module.

Interesting what you say about the clockspring Afco as those could be my symptoms, it will not clear the fault even for half a second and my pre-tensioner connectors look good and both pre-tensioners have the same resistance. I am going to double check this with jump leads but they look alright it just won't go out even for a bit with whatever I do with them.

Just one question Afco, or anyone, what is the clockspring? I haven't heard of this at all.

Also even after you changed that would multiscan not turn it off? You had to use MES?

Thanks

the clockspring is the round thing that make the connection between the airbag ecu and the airbag it sits between the steering wheel(attached to it) and the plastic trim behind it

 

[Acebaraka]

So just to update and finish this thread.

I finally got round to sorting this out and it turns out it was the passenger pre-tensioner just as MultiECUscan said it was (it said driver but as you all know that's the passenger side over here)

The connector looked great, the resistance of the pre-tensioner was the same as the driver side and the same as the the new (second hand eBAy) one but changing it allowed MultiECUscan to clear the fault and it stayed clear so all good.

So apparently sometimes no way of knowing if a pre-tensioner is faulty other than by changing it and also try the simple obvious things first